The treatment of pain has great importance in medicine. There is a worldwide need for effective methods of treating pain. The urgent need for action for patient-friendly and purposeful treatment of chronic and non-chronic pain conditions, this being taken to mean the successful and satisfactory treatment of pain for the patient, is documented in the large number of scientific papers which have recently appeared in the field of applied analgesics and fundamental research on nociception.
Conventional opioids, such as morphine, are extremely effective in the treatment of severe to the severest pain. However, their undesirable side effects include inter alia respiratory depression, nausea, sedation, constipation and tolerance development. In addition, they are less effective in the event of neuropathic or incidental pain, suffered in particular by patients with tumors.